The route is only for fast hikers or multi-day hikes (for example, with a stay at Kärlingerhaus).
Take the earliest boat you can get (in summer 8:00). Only go on a day without risk of rain and preferably without rain in the previous days. The path is often slippery. The descent is T4 too (IMO).
Approximate movement durations with a fast group: 2-2,5h Salet to Wasseralm. 1h Wasseralm to Halsköpfl. 45min Halsköpf to Grünsee. 2h Grünsee to Salet.
extended version of https://www.hiking-buddies.com/routes/routes_list/1666/